U.S. patent number 7,863,764 [Application Number 11/856,755] was granted by the patent office on 2011-01-04 for powertrain with torque converter-mounted generator for multiple voltage electrical power and method for assembling same.
This patent grant is currently assigned to GM Global Technology Operations, Inc.. Invention is credited to Robert Franklin Combs, Leroy K. Johnson, David J. Sagers.
United States Patent |
7,863,764 |
Combs , et al. |
January 4, 2011 |
Powertrain with torque converter-mounted generator for multiple
voltage electrical power and method for assembling same
Abstract
A torque converter-mounted generator is provided that, along
with power electronics, offers at least two types of electrical
power output and may be attached to a transmission without
impacting the axial length of a powertrain in comparison to a
powertrain with an identical transmission and a torque converter
not having a generator mounted thereto. Different torque-converter
mounted generators and power electronics configurations providing
different combinations of electrical power voltages may be offered
for use with a given transmission type, thus allowing flexibility
in meeting customer needs without unduly impacting assembly of the
powertrains. A method of assembling transmissions is also
provided.
Inventors: |
Combs; Robert Franklin
(Mulberry, IN), Sagers; David J. (Indianapolis, IN),
Johnson; Leroy K. (Brownsburg, IN) |
Assignee: |
GM Global Technology Operations,
Inc. (Detroit, MI)
|
Family
ID: |
40453283 |
Appl.
No.: |
11/856,755 |
Filed: |
September 18, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20090071784 A1 |
Mar 19, 2009 |
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Current U.S.
Class: |
290/32; 310/112;
310/179 |
Current CPC
Class: |
B60L
50/16 (20190201); B60L 15/20 (20130101); B60K
6/40 (20130101); B60K 6/48 (20130101); H02K
7/006 (20130101); B60L 53/14 (20190201); H02K
11/048 (20130101); Y02T 10/7072 (20130101); B60K
2006/268 (20130101); Y02T 10/72 (20130101); B60L
2240/423 (20130101); B60L 2240/12 (20130101); Y02T
90/14 (20130101); Y02T 10/70 (20130101); B60L
2240/443 (20130101); Y02T 90/12 (20130101); Y02T
10/64 (20130101); Y02T 10/62 (20130101); B60L
2210/30 (20130101); B60L 2260/26 (20130101); B60L
2210/40 (20130101); F02N 11/04 (20130101) |
Current International
Class: |
H02P
9/04 (20060101) |
Field of
Search: |
;290/32 ;477/3
;310/112,113,114,68R,179,180,184,216.109 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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01255460 |
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Oct 1989 |
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JP |
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05268752 |
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Oct 1993 |
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JP |
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Primary Examiner: Gonzalez; Julio
Attorney, Agent or Firm: Quinn Law Group, PLLC
Claims
The invention claimed is:
1. A powertrain comprising: a transmission housed within a
transmission housing; a torque converter operatively connected with
the transmission and housed within a torque converter housing;
wherein the torque converter housing is secured to the transmission
housing; a generator having a rotor secured to the torque converter
and a stator secured to the torque converter housing; power
electronics operatively connected with the generator; wherein the
generator and power electronics are configured to provide
electrical power at multiple voltage levels; wherein the generator
generates electrical power at at least two different voltage
levels; wherein the stator includes first and second sets of stator
segments; and wherein the first and the second sets of stator
segments each have one of a respective different number of windings
and a respective different number of segments to provide a
different one of the at least two different voltage levels.
2. The powertrain of claim 1, wherein the stator includes
multi-phase power outputs.
3. The powertrain of claim 1, further comprising: an engine
operatively connected to the torque converter for powering the
transmission; wherein said power electronics are configured to
provide electrical power to said stator to drive said rotor,
thereby operating the generator in a motoring mode for at least one
of starting the engine and providing power to the transmission in
tandem with the engine.
4. The powertrain of claim 1, wherein the rotor and the stator are
concentrically arranged to define a radial gap therebetween.
5. The powertrain of claim 1, wherein the rotor and the stator are
concentrically arranged to define an axial gap therebetween.
6. The powertrain of claim 5, wherein the rotor is a first rotor
and the axial gap is a first axial gap, and further comprising: a
second rotor concentrically arranged with the stator to define a
second axial gap therebetween; wherein the stator is arranged
axially between the first rotor and the second rotor.
Description
TECHNICAL FIELD
The invention relates to a powertrain with a torque
converter-mounted generator and to a method of assembling
powertrains.
BACKGROUND OF THE INVENTION
Motor vehicles, especially those of the military or commercial
type, often include power take-off units or add-on devices
connected with the vehicle engine and transmission for providing
electrical power for external or "offboard" uses such as powering
industrial equipment or tools. Such power take-off units and add-on
devices require a significantly time-consuming installation
process. Additionally, the overall axial length of the transmission
is typically increased significantly with the incorporation of
these devices into the vehicle powertrain. The application of a
specific type of transmission by different customers varies widely,
as does onboard and offboard power needs.
SUMMARY OF THE INVENTION
A torque converter-mounted generator is provided that, along with
power electronics, offers at least two electrical power output
voltages and may be attached to a transmission without impacting
the axial length of a powertrain in comparison to a powertrain with
an identical transmission and a torque converter not having a
generator mounted thereto. Different torque-converter mounted
generators and power electronics configurations providing different
combinations of power output voltages may be offered for use with a
given transmission type, thus allowing flexibility in meeting
customer needs without unduly impacting assembly of the
powertrains.
Specifically, a powertrain within the scope of the invention
includes a transmission housed within a transmission housing, and a
torque converter operatively connected with the transmission and
housed within a torque converter housing. The torque converter
housing is secured to the transmission housing. A generator with a
rotor is secured to the torque converter. The generator also has a
stator that is secured to the torque converter housing. Power
electronics are operatively connected with the generator. The
generator and power electronics are configured to provide
electrical power at multiple voltages. Voltage may be a relatively
low voltage required for powering onboard vehicle accessories,
while another voltage may be at a relatively high voltage for
offboard power needs. As used herein, "onboard" refers to
components normally connected with the vehicle at all times,
including when the vehicle is in motion, while "offboard"
components are those not integral with the vehicle and typically
connected to the vehicle only when it is stationary.
In some embodiments, the generator may generate electrical power at
two or more different voltages, such as if the stator includes
first and second sets of stator segments adapted to provide the two
different electrical voltages. Alternatively, the generator may
generate electrical power at only one voltage that is then
converted to different voltages for electrical power output by
different components of the power electronics.
In one embodiment, the power electronics are configured to provide
electrical power to the stator to drive the rotor, thereby
operating the generator in a motoring mode for starting the engine
and/or providing torque to the transmission in tandem with the
engine.
Within the scope of the invention, the design of the torque
converter-mounted generator may vary widely. For example, the
stator and rotor may be configured with a radial gap or an axial
gap, in which case there may be two rotors concentrically arranged
with the stator and axially spaced on either side of the stator.
The stator may have windings and multi-phase power outputs. The
rotor may include different sets of magnets.
A method of assembling powertrains includes installing a first
torque converter-mounted generator on a first transmission of a
first type, and operatively connecting a first configuration of
power electronics to the first torque converter-mounted generator.
The first torque converter-mounted generator and the first
configuration of power electronics provide electrical power at
least two different voltages. The method further includes
installing a second torque converter-mounted generator on a second
transmission of the first type, wherein the first transmission and
the second transmission are substantially identical. The method
further includes operatively connecting a second configuration of
power electronics to the second torque converter-mounted generator.
The second torque converter-mounted generator and the second
configuration of power electronics provide electrical power
voltages different than the two voltages provided by the first
torque converter-mounted generator and the first configuration of
power electronics. Notably, only one of the voltages provided by
each of the powertrain embodiments need be different in order for
the two voltages provided by each to be considered different (e.g.,
the first torque converter-mounted generator and first
configuration of power electronics may offer a low voltage power of
28 volts direct current, just as the second torque
converter-mounted generator and second configuration of power
electronics does, but different higher voltage power (e.g., 220
volts direct current versus 270 volts direct current) may be
provided by the two embodiments. Preferably, the assembly of the
transmissions with the different torque converters may occur on the
same assembly line in a factory. Thus, customer needs for different
types of electrical power may be addressed as the powertrains are
assembled.
The above features and advantages and other features and advantages
of the present invention are readily apparent from the following
detailed description of the best modes for carrying out the
invention when taken in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration in partial cross-sectional side
view of a first powertrain including a transmission, and engine, a
torque converter with a first type of generator mounted thereon,
and power electronics, providing electrical power at two different
voltages;
FIG. 2 is a schematic cross-sectional illustration of the torque
converter-mounted generator of FIG. 1;
FIG. 3 is a schematic illustration in partial cross-sectional side
view of a second powertrain including a transmission of the same
type of the transmission of FIG. 1, an engine of the same type as
the ending of FIG. 1, and a torque converter with a second type of
generator mounted thereon, and power electronics, providing
electrical power at voltages different than the voltages provided
by the generator of FIGS. 1 and 2; and
FIG. 4 is a schematic illustration of a third powertrain including
a transmission and an engine identical to those of FIG. 3, and a
torque converter without a generator mounted thereon.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, wherein like reference numbers refer to
like components, FIG. 1 shows a powertrain 10 that includes an
engine 12, such as an internal combustion engine or a diesel
engine. The powertrain 10 further includes a torque converter 14
housed within a torque converter housing 16 and a transmission 18
housed within a transmission housing 20. The engine crankshaft 22
is connected with an input shell 26 of the torque converter 14 via
a flex plate 24 or other interface secured by bolts 28 or other
fastening mechanisms to the torque converter input shell 26. As is
known, the torque converter 14 forms a fluid coupling between the
engine 12 and the transmission 18, providing torque multiplication
via an impeller or pump portion rotating with the input shell 26
that forms a viscous coupling with a turbine portion rotating with
an input member 30 of the transmission 18. The internal components
of the torque converter 14, including the pump portion and turbine
portion are well known and are not shown in FIG. 1. The torque
converter 14 may be either stamped or machined steel or stamped
aluminum. The transmission 18 utilizes intermeshing gears, such as
planetary gear sets or gear planes in a countershaft arrangement,
as well as selectively engagable torque-transmitting mechanisms,
such as synchronizers, clutches and/or brakes, to establish torque
transmission at various speed ratios to a transmission output
member 31.
A torque converter-mounted generator 34 is provided that
establishes, along with multiple sets of power electronics
(discussed below) multiple power outputs for onboard and/or
offboard power needs. The torque converter-mounted generator 34
includes a rotor 36 secured to the torque converter 14,
specifically, to the torque converter input shell 26 for rotation
therewith. The generator 34 further includes a stator 38 mounted to
the torque converter housing 16 such that the stator 38 remains
stationary with the torque converter housing 16. The rotor 36 and
stator 38 are concentrically arranged about an axis of rotation of
the engine crankshaft 22 and the transmission input member 30 and
define a circumferential radial air gap 32 therebetween. The engine
12 includes an engine block 40 secured by bolts 42 or other
fasteners to the torque converter housing 16. The torque converter
housing 16 is also secured by bolts 44 or other fasteners to the
transmission housing 20. The engine block 40, torque converter
housing 16 and transmission housing 20 are stationary components.
Preferably, the stator 38 is cooled by oil or water coolants in any
known manner.
Referring to FIG. 2, the torque converter-mounted generator 34 is
shown in cross-sectional view at the arrows indicated in FIG. 1. In
this view, it is evident that the stator 38 is actually comprised
of different stator segments, including a first set of stator
segments 46 and a second set of stator segments 48. The first set
of stator segments 46 includes interpole slots 50 in which
three-phase stator windings 52 are nested. The stator windings 52
form end turns 53 visible in FIG. 1. The number of segments in the
first set of stator segments 46 and the number of windings 52 is
exemplary only in FIG. 2, and is selected to achieve a desired
first output voltage, as discussed below. The second set of stator
segments 48 includes interpole slots 50A in which three-phase
stator windings 52A are nested. The stator windings 52A also form
end turns, although these are not visible in the cross-section of
the generator 34 taken in FIG. 1. The number of segments in the
second set of stator segments 48 and the number of windings 52A are
also selected to achieve a second desired output voltage, different
than the first output voltage, as discussed below. The stator
segments 46, 48 are bolted or otherwise secured to the torque
converter housing 16 with bolts 54 as indicated.
The rotor 36 of the torque converter-mounted generator 34 has
magnets 56 circumferentially spaced therearound. The number of
magnets 56 is selected to optimize the desired first and second
output voltages. The rotor 36 is secured with bolts 58 or any other
fastening method to the torque converter 14 so that it rotates with
the torque converter 14. The bolts 58 are shown in an exemplary
arrangement only, and may be of a different number, spacing, or
location than that shown. The radial air gap 32 is shown between
the stator segments 46 and 48, and the rotor 36.
When the engine crankshaft 22 turns, the input shell 26 and rotor
36 are turned. The magnetic flux of the rotating magnets 56
generates current flow in the windings 52 and 52A of stator 38.
Referring again to FIG. 1, the powertrain 10 incorporates power
electronics; specifically, a first set of power electronics 60 in
electrical communication with the first set of stator segments 46
as well as a second set of power electronics 62 in electrical
communication with the second set of stator segments 48. Together,
the first and second types of power electronics 60, 62 may be
referred to as a first configuration of power electronics. The
first set of stator segments 46 and the first set of power
electronics 62 are configured to provide electrical power at a
first voltage, such as a relatively low 28 volt direct current
(VDC). The second set of stator segments 48 and the second set of
power electronics 62 are configured to provide electrical power at
a second voltage, such as a relatively high 270 volt direct
current. The first set, or lower voltage, power electronics 60
includes a first power connection 64 connected with the first set
of stator segments 52 which can function as a first power output,
The first power connection 64 communicates power to a low voltage
power module 66, which includes an inverter and electronic
controller. The low voltage power module 66 is operable to convert
the three-phase alternating current provided by the first set of
stator segments 52 into power in the form of 28 volt direct current
to be stored in a low voltage battery 68. The controller function
of the power module 66 directs the battery 68 to provide energy to
vehicle accessories 70 configured to function on power at the low
voltage (e.g., 28 Volt) level. The vehicle accessories 70 may
include air conditioning, audio systems, and any other onboard or
offboard electrically-powered components designed to run on the low
voltage power provided by the first set of power electronics.
The second set of power electronics 62 includes a second power
connection 72 that connects to the second set of stator segments 48
and functions as a second power output for the second, higher
voltage, type of electrical power. The second power connection 72
communicates power to a high voltage rectifier and controller
module 74 which functions as an export power rectifier and
controller. The high voltage rectifier and controller module 74 is
operable to convert the three-phase alternating current provided by
the three-phase stator windings 52A into power in the form of 270
volt direct current that is provided to an external power load 76
under the control of the controller portion of the high voltage
rectifier and controller module 74. The external power load 76 may
include, for example, offboard industrial and utility equipment or
tools, or an onboard load, such as refrigeration for a trailer in
transit.
Referring to FIG. 3, a second embodiment of a powertrain 10A
illustrates a second type of torque converter-mounted generator 34A
utilized with an engine 12A and transmission 18A interconnected in
the same manner as the corresponding components of FIG. 1. In fact,
the engine 12A is an identical type engine as engine 12 and the
transmission 18A is an identical type transmission as the
transmission 18. In the powertrain 10A however, the torque
converter-mounted generator 34A is of a different configuration,
providing different voltage outputs, than the torque
converter-mounted generator 34. Thus, a transmission manufacturer
can offer the transmission represented as 18 in FIG. 1 and 18A in
FIG. 3, modified according to a customer's specific power output
needs, by choosing one of the torque converter-mounted generators
34 or 34A, designed with customized low and high voltage outputs.
Additionally, the transmission 18A may also be offered with a
traditional torque converter 14B, i.e., one without a generator
mounted thereon, as illustrated in FIG. 4, as the traditional
torque converter 14B and the torque converters with generators
mounted thereon 14, 14A, occupy essentially the same axial
packaging space, with only a different torque converter housing
required for each different design.
The engine 12A includes an engine block 40A secured by bolts 42A or
other fasteners to the torque converter housing 16A. The torque
converter housing 16A is also secured by bolts 44A or other
fasteners to the transmission housing 20A. The engine block 40A,
torque converter housing 16A and transmission housing 20A are
stationary components.
Referring in more detail to FIG. 3, the torque converter-mounted
motor generator 34A is an axial gap air core generator that
includes a stator 38A mounted to the torque converter housing 16A
such that the stator 38A remains stationary with the torque
converter housing 16A. The stator 38A includes multiple stator
segments, circumferentially-spaced similar to those of FIG. 3,
allowing multiple stator segments for multiple voltage outputs at
the same time with separate output terminals, as discussed below.
The torque converter-mounted generator 34A also includes a first
rotor 36A and a second rotor 36B secured to the torque converter
14A, specifically, to the torque converter input shell 26A for
rotation therewith. The rotors 36A, 36B and stator 38A are
concentrically arranged about an axis of rotation of the engine
crankshaft 22A and the transmission input member 30A, with the
stator 38A sandwiched between the rotors 36A, 36B such that axial
air gaps 32A, 32B are defined between each of the rotors 36A, 36B
and the stator 38A, respectively. Each rotor has two sets of
magnets 56A and 56B spaced circumferentially therearound, each set
being characterized by different strengths, inducing different
current flow in the axial core windings of the stator 38A.
Different voltage outputs associated with the magnets 56A, 56B are
utilized to provide different types of power for onboard and/or
offboard use, as described below. Those skilled in the art readily
understand the construction of axial gap air core generators.
The powertrain 10A incorporates a first set of power electronics
60A in electrical communication with the stator 38A via a first
power connection 64A. The first set of power electronics 60A is
configured for a first electrical power voltage, such as a lower
voltage 24 volt direct current (VDC). The first set of power
electronics 60A includes a low voltage power module 66A, including
an inverter and an electronic controller, and a low voltage battery
68A operatively connected to vehicle accessories 70A. The
components of the first set of power electronics 60A are configured
and function similar to those like components of the first set of
power electronics 60 of the powertrain 10 of FIG. 2, except that
the low voltage power module provides 24 volt direct current to the
battery 68A.
The powertrain 10A also incorporates a second set of power
electronics 62A in electrical communication with the stator 38A via
a second power connection 72A. Together the first and second sets
of power electronics 60A, 62A, may be referred to as a second
configuration of power electronics. The second set of power
electronics 60A is configured for a second electrical power
voltage, such as a higher voltage 220 volt direct current. The
second power connection 72A communicates power to a high voltage
rectifier and controller module 74A which functions as an export
power rectifier and controller. The high voltage rectifier and
controller module 74A is operable to convert three-phase 220 volt
alternating current provided by the stator 38A into power in the
form of 220 volt direct current that is provided to an external
power load 76A under the control of the controller portion of the
high voltage rectifier and controller module 74A. The external
power load 76A may include, for example, offboard industrial and
utility equipment of tools, or an onboard load, such as
refrigeration for a trailer in transit. These components of the
second set of power electronics 62A are configured and function
similar to those like components of the second set of power
electronics 62 of the powertrain 10 of FIG. 1, except that the high
voltage rectifier and controller module 74A provides power at 220V
to the external power load 76A.
The second set of power electronics 62A also includes componentry
enabling the torque converter-mounted generator 34A to function as
a motor to start the engine 12A or to provide power in tandem with
the engine 12A to the transmission 18A, providing hybrid propulsion
capability. Thus, the torque converter-mounted generator 34A may be
referred to as a motor/generator. Specifically, the second set of
power electronics 62A includes a high voltage alternating current
to direct current power module 80A that functions as a power
inverter and as an electronic controller to invert power from a
high voltage alternating current, such as 220 volts alternating
current, to a high voltage direct current, such as 220 volts direct
current. The high voltage direct current is then stored in a high
voltage battery 82A. A high voltage electronic controller 84A is
configured to direct stored energy from the battery 82A to the
stator 38A when operating conditions warrant starting the engine
12A, or when the engine 12A is already powering the transmission
18A and additional torque is required and may be provided by the
motor/generator 34A. It should be appreciated that the direct
current power module 80A, the battery 82A and the high voltage
electronic controller 84A may also be employed on the powertrain 10
of FIG. 2 such that the torque converter-mounted generator 34 could
also function as a motor.
As indicated in FIGS. 2 and 3, different powertrains may be
constructed with the same type of transmission and engine, but with
different torque converter-mounted generators connected
therebetween. The choice of torque converter-mounted generator in
terms of the power outputs it is configured to provide may be
driven by specific customer needs. Alternatively, if onboard or
offboard power is not required for a specific powertrain
implementation, a powertrain 10B, configured as shown in FIG. 4,
may be provided with an engine 12B, a transmission 18B and a torque
converter 14B, within a torque converter housing 16B, that is not
equipped with a generator. The engine 12B may be of the same type
as engines 12 and 12A, and the transmission 18B may be of the same
type as transmissions 18 and 18A.
Preferably, the power outputs of the various generators 34, 34A are
common and the power electronics 60, 62, 60A, 62A are common, so
that the generators and power electronics can be used for various
different types of transmissions as well. Various power electronic
configurations, including those of the following electric power
voltages, are preferably available for connection to the common
power outputs of the generators 34, 34A: 600 Volts DC, 12 Volts DC,
42 Volts DC, 110/220 Volts (60 Hz) alternating current "AC", 220
Volts (50 Hz AC), 24 Volts DC and 270 Volts DC.
Accordingly, a method of assembling powertrains, described with
respect to the powertrain embodiments of FIGS. 1-4, includes
installing a first torque converter-mounted generator 34 on a first
transmission 18 of a first type. This may include attaching a
torque converter housing 16 to a transmission housing 20. The
method further includes operatively connecting a first
configuration of power electronics 60, 62 to the first torque
converter-mounted generator 34. The first torque converter-mounted
generator 34 and the first configuration of power electronics 60,
62 provide electric power at least two voltages (e.g., 28 VDC and
270 VDC).
The method also includes installing a second torque
converter-mounted generator 34A on a second transmission 18A of the
first type that is substantially identical to the first
transmission 18. This may include attaching a different torque
converter housing 16A to a transmission housing 20A that is
identical to the transmission housing 20. The method then includes
operatively connecting a second configuration of power electronics
60A, 62A, to the second torque converter-mounted generator 34A. The
second torque converter-mounted generator 34A and the second
configuration of power electronics 60A, 62A provide electric power
at voltages different than the two voltages provided by the first
torque converter-mounted generator 34 and the first configuration
60, 62 of power electronics. Within the scope of the method, a
torque converter 14B that does not have a generator mounted thereon
may be connected with a transmission 18B identical to the
transmissions 18 and 18A and with an engine 12B identical to the
engines 12 and 12A. Thus, the method enables a given transmission
and engine combination to be connected with different torque
converters (with different types of generators, a motor/generator,
or no generator mounted thereto) and different power electronic
configurations (or no power electronics in the case of a torque
converter without a generator) to meet a customer's specific
electrical power needs.
While the best modes for carrying out the invention have been
described in detail, those familiar with the art to which this
invention relates will recognize various alternative designs and
embodiments for practicing the invention within the scope of the
appended claims.
* * * * *